If you want to edit incredibly slowly…use After Effects.
Like others have said, it is not a video editing program. The biggest problem is that you can’t just watch your timeline, you need to render every time, and there is a limit to that type of playback as well.
With a video editing program, (with most codecs), you can just watch your clips instantly if there are no filters applied.
Even if I’m working on a piece that is 90% graphics, I’ll still make a content string inside an editing program and then import those selects into After Effects. After Effects is great at a lot of things, but video editing is not one of them. It would be like using Photoshop to write a book.
*On a side note. I am a little alarmed that you don’t know what a NLE program is. Are you getting a little over your head with these videos? Perhaps you should contract an editor to help you with getting some of the first videos out the door. You can be upfront and tell him or her you want to be trained as well. It would be a good investment. There are a ton of caveats with producing videos that I’m guessing you are unaware of.
Good luck.
Best regards,
Kevin Camin